This invention relates generally to light bars for emergency vehicles and, more particularly to the construction of a light bar capable of accommodating a multiplicity of component configurations and the method of making such a light bar.
Light bars are utilized on many different types of vehicles such as police cars, ambulances, wreckers, etc. to give visual indications of their presence during emergencies. Light bars typically include a variety of different components such as stationary lamps, rotating lamps, reflectors, and a siren. The dome of a light bar is normally tinted to impart the desired color, typically red, blue or yellow, to the light emitted. If it is desired to emit light of different colors from different lamps, a colorless dome is used and lenses of the desired colors are placed on the various lamps.
The components typically vary in size and configuration, with a consequent variation in the pattern of holes in their respective supports for receiving the fasteners used to attach them to the base of the light bar. Thus, the base is punched with a particular array of holes used to accommodate a particular arrangement of components in the bar, the holes in each location along the base corresponding uniquely to the fastener holes in the component to be mounted at that location.
As a result, the array of holes in the base necessarily varies as the arrangement of components in the bar is varied. This is a practical problem because the desired arrangement of components varies from jurisdiction to jurisdiction, and sometimes from vehicle to vehicle in a particular jurisdiction. A resultant complication and expense is, thus, introduced into the process of manufacturing light bars, since bases must be custom punched for each desired component arrangement.
A further complication in both the manufacture and use of light bars arises from the variation in light color requirements as a function of the particular use to which the light bar is put. Thus, for example, some jurisdictions require one color light for fire vehicles, another for police vehicles, and still others for ambulances and maintenance vehicles. Although the light bars may otherwise be standardized and interchangeable among vehicles of different types, the color limitations may require dedication of a particular light bar to a single use. Economies in the purchase and utilization of light bars could be achieved if means were provided for simple modification of the bar to change the color of light projected from its lamps.
Some codes and practices further require that light of one color be projected forwardly of an emergency vehicle and light of another color be projected to the rear. Meeting such requirements may present difficulty where color is imparted to the projected light by placement of a colored lens over the lamps mounted inside the bar.